1. Field of the Invention
This invention relates to a packaging method for integrated circuits, it more specifically relates to an integrated circuit packaging method and design comprising methods and processes such as assembly of chip and leadframe, wire-bonding, globtopping, curing, and singulation.
2. Description of the Related Art
The prior art integrated circuit structure is as shown in FIG. 1, a singulated chip 10 is attached to leadframe unit 20, wherein said leadframe unit 20 comprising of multiple rows of leads 201, at the selected surface of leads 201 and chip 10 is wire-bonded with wire 30, leads 201 are used as the out-connecting components for chip 10; since wire 30 is very delicate, it is commonly sealed through packaging method in the prior art to prevent its damage from external forces, that is, mold is used to enclose chip 10 and leadframe unit 20, then insulating encapsulant is injected into the mold such that an encapsulated body 40 is formed to enclose chip 10 and leadframe unit 20 ; furthermore, as shown in FIG. 2, the packaged integrated circuit is singulated to separate the chip for use by other end users.
In the prior art packaging method, Transfer Molding method has to be used, therefore, multiple types and sizes of mold have to be prepared, the packaging cost thus can not be lowered, and too many molds could also cause QC troubles; furthermore, when the mold enclose chip 10 and leadframe 20, the gaps among leads 201 are not blocked, therefore, when encapsulant is injected under high pressure, encapsulant usually overflows outside leadframe 20, this could cause defect in the packaged product; if any stop component is used to stop the overflow of encapsulant among leads 201, it would be technically very difficult since leads 201 of leadframe unit 20 are very delicate, not only a lot of trouble could be encountered in the process, it could also bring damage to leads 201. Moreover, in the prior art, integrated circuit is singulated to separate (to exclude leadframe and other junk material), therefore, only one by one dicing can be performed (please refer to FIG. 2), and the efficiency during mass production is thus reduced.